The long-term objective is to obtain a better understanding of the structural basis for information processing in the vertebrate retina. The ganglion cells provide an ideal opportunity for studies which correlate structure with function because of their ideal location and easy accessibility for both morphological and physiological analysis. The study will combine use of a newly-developed monoclonal antibody (AB5), which is specific for ganglion cells, with a variety of anatomical techniques to study the structure and synaptic relationships of retinal ganglion cells in both the adult and developing rabbit. Specific aims for the proposed 3 year study include: 1) A light and electron microscopical immunocytochemical analysis to characterize AB5-labelling of ganglion cells and to study the structure and intraretinal synaptic relationships of the AB5-labelled ganglion cells. 2) A light and electron microscopical immunocytochemical analysis to characterize AB5-labelling of ganglion cells in the developing retina and to study the development of the synaptic relationships of the AB5-labelled ganglion cells. 3) A double-label electron microscopical study combining the techniques of AB5 immunocytochemistry and autoradiography to study the neurotransmitter-specific input to the rabbit retinal ganglion cells. The conventional neurotransmitter candidates GABA and glycine will be investigated. 4) A double-label electron microscopical study combining the techniques of AB5 immunocytochemistry and autoradiography to study the development of neurotransmitter-specific synaptic input to the rabbit retinal ganglion cells.